With the rapid development and progress of information technology, the consumer electronic products, such as portable storage and video/audio media, are widely used in the fields of data read/write and video image. Generally, the universal serial bus (USB) protocol is utilized as a communication bus which is served as the communication interface between the electronic product and the host unit. The USB protocol is developed from version 1.0 to version 3.0 in order to speed up the read/write process of the data stream of the electronic product. The USB 3.0 gradually becomes a standard interface for high-speed data transmission of the electronic product for increasing the access efficiency of the data.
The receiver and transmitter of the electronic product receive the information from the host unit (e.g. computer system) or transmits message to the host unit based on USB 3.0. An independent crystal oscillator or oscillation circuit has to be installed in the receiver and transmitter for providing a reference clock signal of the data transmission and reception between the receiver/transmitter and the host unit. However, the reference clock signal does not synchronized to the transmission frequency of the host unit. Therefore, an elastic buffer is disadvantageously disposed in the electronic product so that the electronic product may extract the signal from the host unit wherein the elastic buffer is used to buffer the frequency difference between reference clock signal and the transmission frequency of the host unit. Consequently, there is a need to develop a novel clock-synchronized method to solve the aforementioned problems.